Sewing machines



Dec. 12, 1961 Filed Jan. 19, 1959 I. A. LESLIE 3,012,532

SEWING MACHINES 2 Sheets-Sheet 1 Inventor LO" l/elann er Par/n Dec. 12,1961 l. A. LESLIE 3,012,532

SEWING MACHINES Filed Jan. 19. 1959 2 Sheets-Sheet 2 l n ven tor fi/enz@0179 United States Patent 3,012,532 SEWING MACHINES I Ivan AlexanderLeslie, Fairwater Parkfield Drive, Nantwich, England Filed Jan. 19,1959, Ser. No. 787,538 Claims priority, application Great Britain Feb.3, 1958 1 Claim. (Cl. 112-258) This invention relates to sewing machinesand has for its object to facilitate the assembly of the mechanisms foroscillating the needle, for feeding the work past the needle and fordriving the machine; and also to enable one or more of said mechanismsto be readily removed from the machine for repair or inspection.

According to the invention, in a sewing machine any one or more of themechanisms for oscillating the needle, for feeding the work and fordriving the said needle oscillating and work-feeding mechanisms, is oreach is in the form of a self-contained unit removably mounted in theframe of the machine. The unit for feeding the work may also include theshuttle or bobbin mechanism.

FIGURE 1 is a side elevation of a sewing machine embodying theinvention.

FIGURE 2 of the accompanying drawing is an exploded view, with the mainframe in longitudinal section, of a sewing machine in accordance withthe invention, the several mechanism units being shown disassembled fromthe frame.

FIGURE 3 is a fragmentary sectional view through the outer end of thehead of the machine, with the needle unit in elevation.

FIGURE 4 is a cross-section through the Work-feed unit when assembled inthe frame, the section being taken on a plane corresponding to lineIV-IV, FIGURE 2.

Referring to the drawings, the frame 1 of the sewing machine is a hollowU-shaped structure formed in one orvmore parts as a sheet-metal pressingor casting, or partly as a pressing or partly as a casting, or otherwiseas found convenient. The rear of this hollow frame is open at the back.The upper arm 2 is tubular, with an open front end, and the lever armcomprises a rear compartment 3 open at the back, and, leading from thiscompartment, a forward extension 4 of open-topped channel section.

The mechanism for oscillating the needle 5 is in the form of aself-contained unit A comprising a casing 6 containing the mechanism andprovided at the rear with a cylindrical extension 7 from which projectsa driving shaft 8 having at its extremity a coupling key 9. Theextension 7 is adapted to fit closely within the open front end of thetop arm 2, and to be removably secured therein by any suitable means,such as by a screw 10 or by a clip or other device; and in order tolocate the unit A with the needle in its correct vertical position, thescrew 10 engages a tapped hole in the extension 7. A rubber sleeve 11may be interposed between the latter and the arm 2 in order to reducenoise and vibration.

The mechanism for feeding the work past the needle 5 is in the form of aself-contained unit B comprising, a trough-like casing 12 enclosing themechanism and from the rear end of which extends a driving shaft 13terminating in a coupling key 14. The unit B may also include the rotaryhook 15 or vibrating shutter or central bobbin for forming the stitches,and its driving means.

The casing 12 is adapted to fit closely within the open front end of thelower arm extension 4 and to be removably secured therein by screws,clips or other suitable means (not shown). The casing 12 is shapedtrans- 3,012,532 Patented Dec. 12, 1961 ice versely to correspond to theinterior of the extension 4, so that it cannot turn therein. A rubberlining 16 may be interposed between the casing 12 and the extension 4 toreduce noise and vibration.

The work-supporting plate 17 may be a separate plate attached by screwsor the like to flanges 18 at the top edges of the extension 4, andrubber may be interposed between these parts. The plate 17 may, ifdesired, be part of the unit B, being attached to the casing 12 or to afixed part inside it.

The motor and mechanism for driving the mechanism of units A and B is inthe form of a self-contained unit C comprising a flanged frame 19 of acontour similar to that of the open rear end of frame 1, and havingmounted thereon an electric motor 20, and wheels 21, 22, each drivenfrom the motor by a belt 23. The upper wheel 21 drives a shaft 24 havingin its end a coupling socket 25 which is a counterpart of the couplingkey 9 on the needle-driving shaft 8. The lower wheel 22 drives a shaft26 having in its end a coupling socket 27 which is a counterpart of thecoupling key 14 on the feed shaft 13.

The frame 19 is adapted to be inserted into the open back of the frame1, with the motor 20 in the compartment 3, and to be removably securedtherein by any suitable means, such as screws 28; and a layer of rubber29 may be interposed between the metallic surfaces to reduce noise andvibration. When the three units A, B, C are being assembled in the frame1, the keys 9, 14, on shafts 8, 13, of units A and B are engaged withthe sockets 25, 27, of the shafts 24, 26 of unit C, so that the drivefrom the motor 20 can be transmitted to the needle, feed andstitch-forming mechanisms.

The assembly of the mechanism of the machine is greatly facilitated bythe use of this invention, as each unit is assembled independently,outside the frame of the machine, and can then be readily mounted in theframe. Also, any one unit can be quickly removed for inspection,cleaning or repair. Instead of the unit C being insertible and removablethrough an open back of the frame, it may be insertible and removablethrough an opening in the base of the compartment 3, the back being leftintact.

I claim:

A sewing machine comprising a hollow main frame having a forwardlyprojecting lower arm open at its front end, a separate self-containedwork feed unit carried by and located substantially entirely within theopen front end of said arm, said work feed unit including a rearwardlyextending drive shaft, means detachably securing said unit in positionin said arm, a drive unit carried by said main frame and including aforwardly extending drive shaft, the rearwardly extending drive shaft ofsaid work feed unit and said forwardly extending drive shaft of saiddrive unit having one end in freely detachable driving engagement witheach other, said work feed unit being in slidable engagement with theopen front end of said arm,

References Cited in the file of this patent UNITED STATES PATENTS862,547 Fefel Aug. 6, 1907 1,581,498 Weis Apr. 20, 1926 1,608,608 MartinNov. 30, 1926 2,063,841 Gooseman Dec. 8, 1936 FOREIGN PATENTS 344,795Germany Nov. 30, 1921

